
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (sqrt (/ (- 1.0 x) 2.0))))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0))));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin(Math.sqrt(((1.0 - x) / 2.0))));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin(math.sqrt(((1.0 - x) / 2.0))))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(sqrt(Float64(Float64(1.0 - x) / 2.0))))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0)))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[Sqrt[N[(N[(1.0 - x), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\sqrt{\frac{1 - x}{2}}\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (sqrt (/ (- 1.0 x) 2.0))))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0))));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin(Math.sqrt(((1.0 - x) / 2.0))));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin(math.sqrt(((1.0 - x) / 2.0))))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(sqrt(Float64(Float64(1.0 - x) / 2.0))))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0)))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[Sqrt[N[(N[(1.0 - x), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\sqrt{\frac{1 - x}{2}}\right)
\end{array}
(FPCore (x)
:precision binary64
(*
(pow
(cbrt
(cbrt
(pow
(fma PI 0.5 (* (- (* PI 0.5) (acos (sqrt (+ 0.5 (* x -0.5))))) -2.0))
2.0)))
3.0)
(cbrt (fma PI 0.5 (* -2.0 (asin (sqrt (- 0.5 (* 0.5 x)))))))))
double code(double x) {
return pow(cbrt(cbrt(pow(fma(((double) M_PI), 0.5, (((((double) M_PI) * 0.5) - acos(sqrt((0.5 + (x * -0.5))))) * -2.0)), 2.0))), 3.0) * cbrt(fma(((double) M_PI), 0.5, (-2.0 * asin(sqrt((0.5 - (0.5 * x)))))));
}
function code(x) return Float64((cbrt(cbrt((fma(pi, 0.5, Float64(Float64(Float64(pi * 0.5) - acos(sqrt(Float64(0.5 + Float64(x * -0.5))))) * -2.0)) ^ 2.0))) ^ 3.0) * cbrt(fma(pi, 0.5, Float64(-2.0 * asin(sqrt(Float64(0.5 - Float64(0.5 * x)))))))) end
code[x_] := N[(N[Power[N[Power[N[Power[N[Power[N[(Pi * 0.5 + N[(N[(N[(Pi * 0.5), $MachinePrecision] - N[ArcCos[N[Sqrt[N[(0.5 + N[(x * -0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision], 1/3], $MachinePrecision], 1/3], $MachinePrecision], 3.0], $MachinePrecision] * N[Power[N[(Pi * 0.5 + N[(-2.0 * N[ArcSin[N[Sqrt[N[(0.5 - N[(0.5 * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
{\left(\sqrt[3]{\sqrt[3]{{\left(\mathsf{fma}\left(\pi, 0.5, \left(\pi \cdot 0.5 - \cos^{-1} \left(\sqrt{0.5 + x \cdot -0.5}\right)\right) \cdot -2\right)\right)}^{2}}}\right)}^{3} \cdot \sqrt[3]{\mathsf{fma}\left(\pi, 0.5, -2 \cdot \sin^{-1} \left(\sqrt{0.5 - 0.5 \cdot x}\right)\right)}
\end{array}
Initial program 9.2%
add-cube-cbrt9.2%
pow39.2%
Applied egg-rr9.2%
add-cube-cbrt9.2%
unpow-prod-down9.2%
Applied egg-rr9.2%
asin-acos10.6%
sub-neg10.6%
*-commutative10.6%
sub-neg10.6%
div-inv10.6%
metadata-eval10.6%
sub-neg10.6%
*-commutative10.6%
sub-neg10.6%
sub-neg10.6%
*-commutative10.6%
distribute-rgt-neg-in10.6%
metadata-eval10.6%
Applied egg-rr10.6%
Final simplification10.6%
(FPCore (x) :precision binary64 (pow (cbrt (+ (* PI 0.5) (* -2.0 (- (* PI 0.5) (acos (sqrt (- 0.5 (* 0.5 x)))))))) 3.0))
double code(double x) {
return pow(cbrt(((((double) M_PI) * 0.5) + (-2.0 * ((((double) M_PI) * 0.5) - acos(sqrt((0.5 - (0.5 * x)))))))), 3.0);
}
public static double code(double x) {
return Math.pow(Math.cbrt(((Math.PI * 0.5) + (-2.0 * ((Math.PI * 0.5) - Math.acos(Math.sqrt((0.5 - (0.5 * x)))))))), 3.0);
}
function code(x) return cbrt(Float64(Float64(pi * 0.5) + Float64(-2.0 * Float64(Float64(pi * 0.5) - acos(sqrt(Float64(0.5 - Float64(0.5 * x)))))))) ^ 3.0 end
code[x_] := N[Power[N[Power[N[(N[(Pi * 0.5), $MachinePrecision] + N[(-2.0 * N[(N[(Pi * 0.5), $MachinePrecision] - N[ArcCos[N[Sqrt[N[(0.5 - N[(0.5 * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision], 3.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\sqrt[3]{\pi \cdot 0.5 + -2 \cdot \left(\pi \cdot 0.5 - \cos^{-1} \left(\sqrt{0.5 - 0.5 \cdot x}\right)\right)}\right)}^{3}
\end{array}
Initial program 9.2%
add-cube-cbrt9.2%
pow39.2%
Applied egg-rr9.2%
asin-acos10.5%
div-inv10.5%
metadata-eval10.5%
*-commutative10.5%
cancel-sign-sub-inv10.5%
metadata-eval10.5%
*-commutative10.5%
+-commutative10.5%
fma-define10.5%
Applied egg-rr10.5%
Taylor expanded in x around inf 10.5%
Final simplification10.5%
(FPCore (x) :precision binary64 (+ (/ PI 2.0) (* 2.0 (- (acos (sqrt (+ 0.5 (* x -0.5)))) (/ PI 2.0)))))
double code(double x) {
return (((double) M_PI) / 2.0) + (2.0 * (acos(sqrt((0.5 + (x * -0.5)))) - (((double) M_PI) / 2.0)));
}
public static double code(double x) {
return (Math.PI / 2.0) + (2.0 * (Math.acos(Math.sqrt((0.5 + (x * -0.5)))) - (Math.PI / 2.0)));
}
def code(x): return (math.pi / 2.0) + (2.0 * (math.acos(math.sqrt((0.5 + (x * -0.5)))) - (math.pi / 2.0)))
function code(x) return Float64(Float64(pi / 2.0) + Float64(2.0 * Float64(acos(sqrt(Float64(0.5 + Float64(x * -0.5)))) - Float64(pi / 2.0)))) end
function tmp = code(x) tmp = (pi / 2.0) + (2.0 * (acos(sqrt((0.5 + (x * -0.5)))) - (pi / 2.0))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] + N[(2.0 * N[(N[ArcCos[N[Sqrt[N[(0.5 + N[(x * -0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] - N[(Pi / 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} + 2 \cdot \left(\cos^{-1} \left(\sqrt{0.5 + x \cdot -0.5}\right) - \frac{\pi}{2}\right)
\end{array}
Initial program 9.2%
asin-acos10.5%
add-cube-cbrt8.3%
associate-/l*8.3%
fma-neg8.3%
pow28.3%
div-sub8.3%
metadata-eval8.3%
div-inv8.3%
metadata-eval8.3%
Applied egg-rr8.3%
fma-neg8.3%
associate-*r/8.3%
unpow28.3%
rem-3cbrt-lft10.5%
sub-neg10.5%
distribute-rgt-neg-in10.5%
metadata-eval10.5%
Simplified10.5%
Final simplification10.5%
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (sqrt (/ (- 1.0 x) 2.0))))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0))));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin(Math.sqrt(((1.0 - x) / 2.0))));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin(math.sqrt(((1.0 - x) / 2.0))))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(sqrt(Float64(Float64(1.0 - x) / 2.0))))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0)))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[Sqrt[N[(N[(1.0 - x), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\sqrt{\frac{1 - x}{2}}\right)
\end{array}
Initial program 9.2%
Final simplification9.2%
(FPCore (x) :precision binary64 (+ (* PI 0.5) (* 2.0 (asin (sqrt 0.5)))))
double code(double x) {
return (((double) M_PI) * 0.5) + (2.0 * asin(sqrt(0.5)));
}
public static double code(double x) {
return (Math.PI * 0.5) + (2.0 * Math.asin(Math.sqrt(0.5)));
}
def code(x): return (math.pi * 0.5) + (2.0 * math.asin(math.sqrt(0.5)))
function code(x) return Float64(Float64(pi * 0.5) + Float64(2.0 * asin(sqrt(0.5)))) end
function tmp = code(x) tmp = (pi * 0.5) + (2.0 * asin(sqrt(0.5))); end
code[x_] := N[(N[(Pi * 0.5), $MachinePrecision] + N[(2.0 * N[ArcSin[N[Sqrt[0.5], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\pi \cdot 0.5 + 2 \cdot \sin^{-1} \left(\sqrt{0.5}\right)
\end{array}
Initial program 9.2%
sub-neg9.2%
+-commutative9.2%
add-cube-cbrt8.5%
distribute-rgt-neg-in8.5%
fma-define8.5%
Applied egg-rr8.5%
add-sqr-sqrt0.0%
sqrt-unprod3.6%
sqr-neg3.6%
sqrt-prod3.6%
add-sqr-sqrt3.6%
fma-define3.6%
Applied egg-rr3.6%
Taylor expanded in x around 0 3.6%
Final simplification3.6%
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (sqrt 0.5)))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin(sqrt(0.5)));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin(Math.sqrt(0.5)));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin(math.sqrt(0.5)))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(sqrt(0.5)))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin(sqrt(0.5))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[Sqrt[0.5], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\sqrt{0.5}\right)
\end{array}
Initial program 9.2%
Taylor expanded in x around 0 4.4%
Final simplification4.4%
(FPCore (x) :precision binary64 (asin x))
double code(double x) {
return asin(x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = asin(x)
end function
public static double code(double x) {
return Math.asin(x);
}
def code(x): return math.asin(x)
function code(x) return asin(x) end
function tmp = code(x) tmp = asin(x); end
code[x_] := N[ArcSin[x], $MachinePrecision]
\begin{array}{l}
\\
\sin^{-1} x
\end{array}
herbie shell --seed 2024062
(FPCore (x)
:name "Ian Simplification"
:precision binary64
:herbie-target
(asin x)
(- (/ PI 2.0) (* 2.0 (asin (sqrt (/ (- 1.0 x) 2.0))))))